This is such a great little tool. I wish I could give it top markings but unfortunately it's a bit flawed.
I got it to be able to play synths directly from my bass. Basically doubling bass lines with synth bass.
First of all, I would not use this live. The triggering is far too quirky. I only use this for recording and even then it requires quite a bit of midi-cleanup for a good result. I can do as many takes as I want and play everything 100% perfect but there's still midi-junk that needs manual editing. This means that recording the midi track at the same time as the actual bass is pretty much hopeless. The midi track needs to be done separately then edited into something useable and THEN re-record the synth part. It requires quite a bit of work to get a good result but in the end I think it's worth it. I'm not a very good keyboard player so I get a much better "feel" when I can record synth basslines with my bass guitar.
I'm actually impressed with the latency performance I'm getting with this little unit. It's far better than any software solution I've tried, like the JamOrigin stuff. So the problem isn't latency or a lack of triggering, it's the fact that any string noise or overtone will generate midi-junk that need to be removed manually in a midi-editor.
In actual performance and usability this device probably shouldn't get more than 3 stars. But it's such a unique little tool, and pretty cheap too, so I'll give it 4 stars total.
Recommended for recording/studio if you're prepared to do some editing but don't even think about using it live!